ASTM-D7639 2018

1.1 This test method covers the use of X-ray fluorescence (XRF) spectrometry for the determination of the mass of zirconium (Zr) coating weight per unit area of metal substrates.

1.2 Coating treatments can also be expressed in units of linear thickness provided that the density of the coating is known, or provided that a calibration curve has been established for thickness determination using standards with treatment matching this of test specimens to be analyzed. For simplicity, the method will subsequently refer to the determination expressed as coating weight.

1.3 XRF is applicable for the determination of the coating weight as zirconium or total coating weight of a zirconium containing treatment, or both, on a variety of metal substrates.

1.4 The maximum measurable coating weight for a given coating is that weight beyond which the intensity of the characteristic X-ray radiation from the coating or the substrate is no longer sensitive to small changes in weight.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.